Over at The New Republic, Lydia Depillis has a good piece on Microsoft’s “Scroogled” campaign, which has moved on from sniping at Google Shopping to charge Gmail with invading its users’ privacy because it scans their e-mail for keywords it can use to display advertising. The ads leave me cold — I find them patronizing and creepy, and generally more damaging to Microsoft’s image than Google’s — and reading her story helped me understand why Microsoft went down this road, and why it’s a bad idea:

Negative ads, as much as politicians might decry them, can have a devastating effect when deployed in a tight race, like last year’s Iowa Republican primary. Perhaps with this in mind, Microsoft hired ex-Clintonite Mark Penn, who pioneered the practice of micro-targeting ads based on consumer behavior, to work his black magic on Google. Penn, however, seems to not have recognized that there are some fundamental differences between consumer product battles and political campaigns, and mistaking one for the other can render them almost completely ineffective.

Microsoft’s anti-Google petition, which seeks signatures from unhappy Gmail campers, has about 6900 signatures as I write this, so it may take it a while to get to its goal of 25,000. I’m convinced that Microsoft will eventually conclude that this whole approach to competition is a self-defeating waste of money, and perhaps the petition’s failure to raise more ire will speed the end of “Scroogled.”